The task is to compare and contrast the two different assessment procedures. You should consider the outcome if a teacher sets an easier test or a harder test.
You many assume that the standard deviation remains the same for each of the tests.

I have no idea where to start. Any help would be greatly appreciated.

NOTE: I have used "a" because i could not find sigma.

Aug 10th 2010, 09:31 PM

matheagle

You should find the probability of each of those intervals using the normal distribution.

P(Z>2) is not close to .5, it's about .02
without looking at the tables I'm sure it's .5-.4772.
Similarly, your third line is off too.
Your second line is wrong too.
P(Z>1) is larger than P(Z>2), which means you have a negative probabilty.
Think about what you wrote and look at the intervals.